Structure model and system simulation of MEMS gyroscope

The model of micro-electro-mechanical system(MEMS) gyroscope structure and monitor circuit is investigated and simulated in Simulink in order to decrease the quadrature error and enhance the gyroscope's precision.Firstly,the model is established based on the ideal gyroscope's model and some imperfect elements,such as the mechanical thermal noise,coupling signal between two modes,and then the parameters are proposed.After that,the close loop drive system is designed based on self-resonant and AGC technology,the amplitude and frequency of drive frame are stabilized at 10 μm and 4048 Hz(drive mode's resonant frequency) respectively within one second.Then,the quadrature error correction and sense force feedback rebalance loops are built.The simulation result indicates that,after correction,the coupling force's amplitude is decreased by 105 times,and its equivalent input angular rate is reduced from 205(°)/s to 6.58(°)/h.Finally,the overall test is made which shows that the scale factor and the threshold value are 21.76 mV/(°)/s and 0.002(°)/s.